Is there a modulus (not remainder) function / operation?

Question

In Rust (like most programming languages), the % operator performs the remainder operation, not the modulus operation. These operations have d

Answer 1

No, Rust doesn't have a built in modulus, see this discussion for some reasons why.

Here's an example that might be handy:

///
/// Modulo that handles negative numbers, works the same as Python's `%`.
///
/// eg: `(a + b).modulo(c)`
///
pub trait ModuloSignedExt {
    fn modulo(&self, n: Self) -> Self;
}
macro_rules! modulo_signed_ext_impl {
    ($($t:ty)*) => ($(
        impl ModuloSignedExt for $t {
            #[inline]
            fn modulo(&self, n: Self) -> Self {
                (self % n + n) % n
            }
        }
    )*)
}
modulo_signed_ext_impl! { i8 i16 i32 i64 }